Bicycle exerciser



FIG. 1 is a perspective view of a bicycle exerciser showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side elevational view, the right side elevational being identical thereof;

FIG. 4 is a rear elevational view, the front elevational view being identical thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a bicycle exerciser, as shown and described. 